arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.00537eess.IVcs.CVcs.LG

利用纵向信息引导的隐后验采样加速MRI

Accelerating MRI with Longitudinally-informed Latent Posterior Sampling

Electrical Engineering , Stanford University , California , USA(电气工程,斯坦福大学,加利福尼亚,美国);Radiology , Stanford University , California , USA(放射学,斯坦福大学,加利福尼亚,美国)

Yonatan Urman, Zachary Shah, Ashwin Kumar, Bruno P. Soares, Kawin Setsompop

AI总结:

提出一种无需纵向配对训练的扩散MRI重建框架,利用临床既往DICOM指导随访k空间重建,并发布多期开放数据集,显著提升加速成像质量。

摘要:

目的:通过在重建过程中纳入受试者既往扫描来加速MRI采集。尽管纵向成像占据临床MRI的很大一部分,但利用既往扫描仍具挑战,原因在于不同扫描期次之间关系复杂,可能涉及显著的解剖或病理变化,并且缺乏同时包含纵向配对和原始k空间、可用于训练深度学习重建模型的开放数据集。方法:我们提出一种基于扩散模型的重建框架,无需纵向配对训练数据。训练期间,我们将所有扫描时间点视为来自同一分布的样本,因此仅需独立图像。推理时,该框架整合临床工作流程中容易获得的、幅值DICOM格式的受试者既往扫描,以指导随访扫描重建。为支持未来开发,我们引入一个开放临床数据集,其中包含多期次配对,既有既往DICOM,也有随访k空间。结果:在多种加速笛卡尔采集策略下,我们的方法始终优于纵向和非纵向基线重建方法。在与既往扫描高度相似的成像区域,我们观察到SSIM最高提升10%、PSNR最高提升2 dB,且在不相似区域没有质量下降。与纵向重建基线相比,我们的方法对不同程度的解剖变化和配准误差表现出稳健性。结论:我们证明,既往扫描可与最先进的基于扩散的重建方法有效结合,以改善图像质量并实现更高的扫描加速,而无需大量纵向配对训练数据集。

英文摘要:

Purpose: To accelerate MRI acquisition by incorporating the previous scans of a subject during reconstruction. Although longitudinal imaging constitutes much of clinical MRI, leveraging previous scans is challenging due to the complex relationship between scan sessions, potentially involving substantial anatomical or pathological changes, and the lack of open-access datasets with both longitudinal pairs and raw k-space needed for training deep learning-based reconstruction models. Methods: We propose a diffusion-model-based reconstruction framework that eliminates the need for longitudinally paired training data. During training, we treat all scan timepoints as samples from the same distribution, therefore requiring only standalone images. At inference, our framework integrates a subject's prior scan in magnitude DICOM format, which is readily available in clinical workflows, to guide reconstruction of the follow-up. To support future development, we introduce an open-access clinical dataset containing multi-session pairs including prior DICOMs and follow-up k-space. Results: Our method consistently outperforms both longitudinal and non-longitudinal baseline reconstruction methods across various accelerated Cartesian acquisition strategies. In imaging regions highly similar to the prior scan, we observe up to 10\% higher SSIM and 2 dB higher PSNR, without degradation in dissimilar areas. Compared to longitudinal reconstruction baselines, our method demonstrates robustness to varying degrees of anatomical change and misregistration. Conclusion: We demonstrate that prior scans can be effectively integrated with state-of-the-art diffusion-based reconstruction methods to improve image quality and enable greater scan acceleration, without requiring an extensive longitudinally-paired training dataset.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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